Computing devices and systems may contain components such as chips that contain high speed interfaces. During design of such systems, and prior to distribution to consumers, these interfaces need to be tested to determine their proper functionality. Such testing may be accomplished by using a testing device that couples to the interface, for example, and testing the timing of signals across the interface. However, modern chips may operate at frequencies higher than that of the testing device. It is therefore desirable to have a built-in self test to test these high speed interfaces.